In accordance with Hess�fs Law, manipulate the following equations and their ƒ¢Hrxn�fs to calculate ƒ¢Hrxn for the reaction HClO4 + NH3 �¨ NH4ClO4...
HClO4(aq)+ LiOH(aq) �¨ LiClO4(aq)+H2O(l)
CH3COOH(aq)+ NH3(aq) �¨ NH4CH3COO(aq)
CH3COOH(aq)+LiOH(aq)�¨ LiCH3COO(aq)+H2O(l)
To calculate the enthalpy change for the reaction HClO4 + NH3 → NH4ClO4, we can use Hess's Law, which states that the enthalpy change for a reaction is the same whether it occurs in one step or through a series of steps.
Here's how you can manipulate the given equations to calculate the enthalpy change for the target reaction:
1. Start with the given equations:
1a. HClO4(aq) + LiOH(aq) → LiClO4(aq) + H2O(l) (Equation 1)
1b. CH3COOH(aq) + NH3(aq) → NH4CH3COO(aq) (Equation 2)
1c. CH3COOH(aq) + LiOH(aq) → LiCH3COO(aq) + H2O(l) (Equation 3)
2. We need to manipulate Equation 2 to match the desired target equation. Notice that Equation 2 involves NH3 and NH4, while the target equation involves NH3 and NH4ClO4. To incorporate ClO4, we can use Equation 1:
2a. Multiply Equation 2 by the stoichiometric coefficient of ClO4 in Equation 1 (which is 1):
CH3COOH(aq) + NH3(aq) → NH4CH3COO(aq) + H2O(l)
Multiply both sides by 1:
1 * (CH3COOH(aq) + NH3(aq) → NH4CH3COO(aq) + H2O(l))
3. We also need to adjust Equation 3 to match the target equation. It involves CH3COOH and LiCH3COO, while the target equation involves HClO4 and NH4ClO4. To achieve this, we can use Equation 1:
3a. Multiply Equation 3 by the stoichiometric coefficients of HClO4 and NH4ClO4 in Equation 1 (which are 1 and 1 respectively):
CH3COOH(aq) + LiOH(aq) → LiCH3COO(aq) + H2O(l)
Multiply both sides by 1:
1 * (CH3COOH(aq) + LiOH(aq) → LiCH3COO(aq) + H2O(l))
4. Now, we need to arrange the manipulated equations to cancel out the common compounds.
Add equations 1a and 2a:
HClO4(aq) + LiOH(aq) + CH3COOH(aq) + NH3(aq) → LiClO4(aq) + H2O(l) + NH4CH3COO(aq)
Subtract equation 3a:
HClO4(aq) + LiOH(aq) + CH3COOH(aq) + NH3(aq) - (CH3COOH(aq) + LiOH(aq) → LiCH3COO(aq) + H2O(l))
= HClO4(aq) + NH3(aq) → LiClO4(aq) + LiCH3COO(aq) + H2O(l)
5. Finally, the resulting equation represents the target equation:
HClO4(aq) + NH3(aq) → NH4ClO4(aq) + LiCH3COO(aq) + H2O(l)
Now, you can calculate the enthalpy change for this equation using the enthalpy changes (ΔHrxn) of the original equations provided, or by looking them up in a reference table. Add the enthalpy changes of the manipulated equations based on their stoichiometric coefficients to find the overall enthalpy change for the target reaction, HClO4 + NH3 → NH4ClO4.